The present invention relates to apparatus and software cooperatively integrating haptic or touching and stereoscopic or three dimensional visual computer interfaces, and is more particularly associated with such apparatuses and software as applied to surgical simulations. The integration in computer generated virtual environments of interfacing of physically felt force-feedback devices (haptic interface devices) that provide the touch or feel sensation and stereoscopic visual interfaces that provide visual three dimensional (3D) objects have not been extensively developed. Those that exist use expensive complex and often ad hoc hardware and software that are difficult to implement and more difficult to service and/or modify. High end, expensive graphic workstations, e.g. Sun Microsystems with specialized hardware and/or software have been so used, but are not amendable to routine use due to the complexity and the expense.
Before proceeding some definitions will be helpful in understanding the invention.
Haptics: Haptics refers to touch. Human sense of touch, human haptics, differs fundamentally from other human sensory modalities in that it is bilateral in nature: to touch an object, the object must “push” back. In computer generated haptics, a computer interface device is used that provides a physical touch to the human that corresponds to the real three-dimensional sense of touch that allows one to feel textures and shapes of objects, modulate objects and even deform objects.
Two major components of computer haptics are collision detection of virtual objects with the haptic interface device, and the determination and application of a force feedback to the user via the haptic interface device. Prior art data structures and algorithms applied to haptic rendering have been adopted from non-pliable surface-based (two dimensional) graphic systems. These prior art techniques and systems are inappropriate and limited due to the different characteristics required for haptic rendering of three dimensional or volumetric soft bodies.
Stereoscopic Display: Stereoscopic herein refers to true 3D viewing of objects. In many prior art systems 3D images are rendered for viewing in a 2D format (e.g., on a flat monitor). True 3D viewing provides the user with the appearance of true depth.
When viewing an object in 3D, both eyes see the object from a slightly different perspective. Each eye perceives a slightly different image, with the brain naturally fusing these two images into one by matching up the similarities and adding in the small difference. The result is the illusion of depth. This process of stereopsis can be simulated by 1) generating the two dimensional image for each eye, and 2) presenting the left eye image only to the left eye and the right eye image only to the right eye. This brief review suffices since stereoscopy is well understood in the art.
Such prior art devices are even more limited if applied to teaching the complex skills associated with medical surgery. Surgery skills are taught on live patients or animals. A computer system that provides true touch and corresponding 3D vision for volumetric soft bodies is needed in the art.
It is an object of the present invention to generate a stereoscopic-haptic computer interface suitable for providing virtual environment.
It is another object of the present invention to result in the illusion of being able to “see” and “touch and feel” 3D virtual environment, for example, a surgeon operating on a virtual patient, but with true-to-life touching and seeing.
It is yet another object of the present invention to produce cost-effective, real-time, interactive, stereoscopic haptic virtual environment with minimal hardware.
It is yet another object of the present invention to transform the virtual environment from a flat, formless 2D experience to a more realistic and solid 3D experience.
It is still another object of the present invention to provide 3D organ models for study by and training of students.